Update activity indicator from a light bar to a point

ash/shelf/shelf_button.h

Index: ash/shelf/shelf_button.h
diff --git a/ash/shelf/shelf_button.h b/ash/shelf/shelf_button.h
index 4a84a61a532d502bb5d7a60e0047ef4beea274a6..7a55f1183789cabf66a3f7fc52d13d9f1adc4118 100644
--- a/ash/shelf/shelf_button.h
+++ b/ash/shelf/shelf_button.h
@@ -90,6 +90,9 @@ class ASH_EXPORT ShelfButton : public views::CustomButton {
   // Updates the status bar (bitmap, orientation, visibility).
   void UpdateBar();
 
+  // Create an light bar image

[bruthig, 2016/04/27 18:56:00]

nit: spelling 'a' instead of 'an'
nit: Use full punctuation, i.e. a period at the end.

[varkha, 2016/04/28 16:49:04]

nit: s/Create/Creates
(https://google.github.io/styleguide/cppguide.html#Function_Comments -
"descriptive ("Opens the file") rather than imperative ("Open the file")").

[yiyix, 2016/05/02 15:55:04]

Done.

[yiyix, 2016/05/02 15:55:04]

Done.

+  void GetActivityIndicatorImage(gfx::Canvas& canvas);

[varkha, 2016/04/28 16:49:04]

Maybe GetIndicatorImage() since we are not planning on doing anything different
based on active state.

[yiyix, 2016/05/02 15:55:04]

Done.

+
   // The shelf view hosting this button.
   ShelfView* shelf_view_;